Treatment of hydrocarbons



Patented Dec. 23, 1941 2,267,142 TREATMENT OF HYDROCARBONS William AlvahSmith, Hamburg, N. Y.

No Drawing. Application March 10, 1938, Serial No. 195,159

6 Claims.

This invention relates to the treatment of hydrocarbon compounds andmixtures thereof, including motor and heating plant fuels andlubricating oils, to improve them as to colon-composition, propertiesand characteristics, and more particularly to their treatment for thepurpose of removing objectionable impurities therefrom for renderingthem more stable in composition and color, and, when the hydrocarboncompounds are lubricating oils, for also reducing the tendency of theoil to sludge or decompose under operating conditions such as in thecrank case of an internal combustion engine. Among examples of theimpurities which may be readily, removed or rendered unobjectionable bythis invention may be mentioned sulphur, whether in a combined oruncombined condition, gums and ,gum 'forming compounds, and unstablehydrocarbon constituents. Heretofore it has been common practice topartially remove some undesirable impurities, including sulphurcompounds,.from hydrocarbon compounds and mixtures thereof, includingboth motor and heating fuels and lubricating oils, some of whichhydrocarbon compounds may be unsaturated, by various acidic treatingagents such as the mineral acids. Sulphuric acid is the mineral acid oracidic treating agent most'commonly used for this purpose, but anhydrousmetallic halides, such as aluminum chloride, are acidic treating agentswhich have also been used for this purpose.

In the usual refining treatment of certain hydrocarbon mixtures, such,for example, as petroleum compounds and particularly the distillatesfrom petroleum cracking stills, it has been found that the unsaturatedhydrocarbons in those mixtures or distillates, that is, hydrocarbonscontaining less than the maximum amount of hydrogen which could beincluded in the combination, are, to a considerable extent, polymerizedinto undesirable hydrocarbon compounds, many of which are resinous incharacter, by the impurities removal agents heretofore employed. Suchundesirable compounds when burned in an internal combustion engine aremore likely to knock or detonate than are the unsaturated compoundsbefore their polymerization.

Frequently these polymerized hydrocarbons have a higher boiling orvaporizing point than is desirable in an internal combustion enginefuel, and therefore are sometimes removed from the desulphurized ortreated mixture and discarded, which decreases the. yield of marketablefuel obtained froma given quantity of untreated hydrocarbon compounds.The polymerization of unsaturated compounds into compounds of highermolecular weight is frequently undesirable where the compounds are to beused in chemical reactions. For example, the unpolymerized andunsaturated compounds are usually chlorinated more easily than aresaturated and polymerized compounds. v

I have discovered that polymerization of the unsaturated compounds canbe largely prevented or minimized, the impurities removal action greatlyaccelerated, and the percentage of impurities removed greatly increased;if the removal action is carried on in the presence of an acceleratingor inhibiting agent or substance. According to my discovery, 8. moredesirable product is obtained, and the impurities removal processes maybe performed at higher temperatures not heretofore feasible ordesirable. Various organic compounds have been found suitable as theaccelerating or inhibiting agent, and may be used in the usual methodsof removing impurities from hydrocarbon compounds.

The selection of the accelerating or inhibiting agent depends somewhatupon the exact nature of the impurities to be removed, the degrees ofunsatu'ration of the hydrocarbon compounds from which the impurities areto be removed, the amount of impurities to be removed, and theconditions under which the removal is to be performed. In general, Ihave found that anhydrous treating agents yield better results thanthose in which waterdilution occurs, and when sulphuric acid is used, Ihave found that in the presence of an inhibiting agent, a concentratedsulphuric acid as near as possible to a one hundred percent pure acidyields more satisfactory results than does commercial oil of vitriolacid, which is usually about ninety-five percent strength. v

The amount of the inhibiting agent which it is desirable to use, whilevarying somewhat with the material to be treated, the impurities to beremoved, and the character of the impurities removal agent, is ingeneral less than the molal quantity of the impurities removal agentemployed.

When the hydrocarbon compounds to be treated are viscous products, theirtreatment may be facilitated by first reducing their viscosity, eitherby heating the same first to reduce the viscosity or by mixing therewiththe necessary amount of a thin liquid such as, for example, gasoline,which viscosity reducing additionagent,

such as gasoline, can be removed readily by peratures.

impurities removal treatment has been completed.

Among the various accelerating and inhibiting agents which may besatisfactorily employed, are the aldehydes including furi'ural and thealiphatic or aryl aldehydes. Outstanding examples of the aliphaticaldehydes which I have found to be very satisfactory in treatinghydrocarbons in accordance with this invention are: acetaldehyde,acetaldol, paraldehyde, butyraldehyde, acrolein and crotolaidehyde. e

Outstanding examples of the aryl aldehydes which are also satisfactoryas the inhibiting agent in accordance with this invention are: citral,citronellal, amyl cinnamicaldehyde, anisicaldehyde, benzaldehyde,nitro-benzaldehyde, cinnamicaldehyde, phenylaceticaldehyde, piperonal,salicylicaldehyde, tolualdehyde, and vanillin.

The inhibiting agent may be added either to the impurities removal agentbeforethe latter is added to the hydrocarbon mixtures, or to thehydrocarbon mixture before the impurities removal agent is added to thehydrocarbon mixture. I prefer to add the inhibiting agent to thehydrocarbon mixture first, and then add the impurities removal agent tothis combined mixture, and the improved method. of treatment may be ofeither the continuous or batch type.

After the hydrocarbon compounds or mixtures thereof have been treatedwith the impurities removal agent and the inhibiting agent, the completemixture may be agitated continuously until the reaction is complete. Thereaction I have found is usually completed within about ten minutes whenthe acid treatment is used for the removal of sulphur, and withinapproximately one half hour if a metallic halide is used as the removalagent. After the reaction is complete, the combined mixture is leftquiescent, whereupon the residue separates out carrying the impuritiesand the treating agent, which then may be removed in any suitable mannersuch as by draining off the supernatant liquid, or by treatment withfullers earth or other adsorbent material, or by washing with water.This treated material may then be subjected to any furtherneutralization or treatment as desired to finish it for the market andto remove any viscosity reducing agent. The residue may be then disposedof as usual in the industry, or treated for the recovery of any valuablecomponents thereof.

Without the use of the inhibiting agent or material, the acidicimpurities removal treatment often required several hours or days inorder to get a high percentage of removal of the impurities. The use ofthe inhibiting agent also speeds up the reaction and makes the removalof impurities more complete, without undesirable polymerization oralteration of the hydrocarbons. I have found that by the use of theinhibiting agent, the action is more rapid at the same temperatures, andone may use higher temperatures during the removal reaction in order tospeed up the reaction without materially increasing the polymerizationof the unsaturated compounds, which polymerization or alteration alwaysheretofore occurred to a very great extent whenever the impuritiesremoval reaction was speeded up by the use of the higher tem- Removal ofimpurities with such an inhibiting agent may be applied to hydrocarbonmixtures in any stage of refinement or in crude form, and produces aproduct which I have found will stand exposure to light moresatisfactorily than products obtained by similar removal processeswithout the use of the inhibitor. The removal of sulphur, for example,when accomplished in the presence of the inhibitor, is more complete fora given amount of the sulphur removing agent than is possible withoutthe use of an inhibitor, and the inhibitor may be used without anychange in the apparatus used heretofore for sulphur removal. The amountof acidic treating agent can be increased to the desired point,impractical otherwise, in order to secure desired refining results. Forexample, in treating Pennsylvania lubricating oils, such quantities of98% sulphuric acid as 30 pounds per barrel or more can be usedsuccessfully and to advantage without excessive loss of the lubricatingmaterial itself.

When motor fuels, such as gasolines, are treated in accordance with thisinvention, the resulting product is non-corrosive, lower in gum content,very much more stable as evidenced by the distillation test residueswhich are relatively light colored, and has better color and colorstability. When heavier petroleum products such as lubricating oils aretreated in accordance with this invention, the color, non-corrosiveness,tendency to sludge or decompose under operating conditions, particularlyunder the conditions existing in the crank cases of internal combustionengines, and the resistance to heat are improved in a similar manner. Ihave also discovered that lubricating oils intended for use inautomotive engine lubrication can be given still greater color stabilityand resistance to sludging by the admixture with the oil of the desired,and preferably a relatively small, amount of quinhydrone. When thequinhydrone is used even in such small amounts as .001% by weight, theresults have been found satisfactory and effective in some cases, butusually a larger percentage of the quinhydrone is preferred up to apercentage which is soluble in the oil.

In the foregoing description, reference has been made to sulphur as oneof the impurities that may be removed or rendered unobjectionwill beunderstood that the exac composition of the impurities which are foundin petroleum hydrocarbons is not definitely k wn, but sulphur is one ofthe major impuri ies found in such petroleum products which can beremoved or rendered uncbiectionable by this invention. It is alsobelieved that the removal of undesirable nitrogen compounds isfacilitated by this invention.

I claim as my invention:

1. A lubricating oil of the type useful in lubricating internalcombustion engines and having increased resistance to sludging in thecrank case of such engines, greater color stability and greaterresistance to decomposition under crank case conditions, which comprisesa petroleum lubricating oil having mixed therewith a relatively smallamount of quinhydrone.

2. The method of treating petroleum lubricating oils of the typeintended for crank case lubrication of internal combustion engines toincrease their color stability and resistance to decomposition andsludging, which comprises mixing with said lubricating oil a relativelysmall quantity of quinhydrone.

3. An improved lubricating composition of low tendency to sludge,comprising a petroleum lubricating oil of the type having a normaltendency to form objectionable sludge and change color in able inaccordance with this lnvntion, but it the crank case of an internalcombustion engine and containing as an addition agent a relatively smallamount of quinhydrone.

4. An improved lubricating composition for crank cases of internalcombustion engines and which in use is relatively stable as to color andhas maximum resistance to heat and minimum corrosiveness. comprising apetroleum lubricating oil of the type known as crank case oil and havinga normal tendency to form objectionable sludge, cause corrosion andchange color in use, and a relatively small amount of quinhydrone as anaddition agent.

5. An improved lubricating composition for crank cases of internalcombustion engines and which in use is relatively stable as to color andha maximum resistance to heat and minimum corrosiveness, comprising apetroleum lubricating oil of the type known as crank case oil and havinga normal tendency to form objectionable sludge, cause corrosion andchange color in use, and quinhydrone as an addition agent in an amountwhich is soluble in the oil and above approximately .001% by weight.

6. The method of treating a petroleum lubrieating oil of a viscositysuitable for use in the crank cases of internal combustion engines, toreduce its tendency to form sludge when used in the crank cases of saidengines, to stabilize its color, and to reduce its corrosiveness, whichcomprises incorporating in said oil a relatively small amount ofquinhydrone as an addition agent in an amount which is soluble in saidoil and above approximately .001% by weight.

WILLIAM ALVAH SMITH.

